The present invention relates generally to print cartridges and more particularly, to a print cartridge lid.
Print cartridges, or pens, are used in many printers. Typically, these print cartridges contain an ink reservoir or multiple ink reservoirs. Each reservoir may contain a foam interior that is saturated with ink. The ink contained within these reservoirs is intended to pass through the pen to media during printing. A lid as used herein is any component attached to the reservoirs. For example, a lid may be used to cover the reservoirs to prevent the ink from leaking out of the reservoirs.
One difficulty associated with such ink cartridges involves the challenge of keeping ink from leaking through joints between the lid and the reservoir. Ink leakage is a significant problem for a user because it may affect the quality of printing and make handling the ink cartridge difficult. For example, if ink does leak out of a reservoir, it may contaminate an adjacent reservoir (causing the colors of two reservoirs to mix). Furthermore, the ink may leak to the exterior of the pen. When such leakage occurs, a user who contacts the pen may be soiled by ink.
The cause of ink leakage may be liquid ink or ink-saturated foam contacting the joint between the reservoir and the lid. If the joints are not sealed then capillary forces may act to transport ink through the joints and to the exterior of the pen or to an adjacent reservoir. To avoid this problem, an internal wall may be used to keep the ink-saturated foam from coming in contact with the joints. Such an internal wall may also be used for other functions, such as alignment of the lid, strengthening of the lid, improvement of mold flow and lid dimensions. When these internal walls intersect with other walls or are in close proximity to another wall, then capillary forces may act to transport ink along the walls through capillary pathways. Ink may be drawn through these capillary pathways from the reservoir into adjacent reservoirs or to exterior surfaces of the print cartridge.
The present invention is directed to a lid for a print cartridge where the print cartridge has an ink reservoir configured to contain ink-permeable foam. The lid typically includes a barrier configured to seal the ink reservoir and a stand-off spaced from the barrier. The stand-off is configured to engage the ink-permeable foam. The lid may also include an alignment structure coupled with the stand-off, and a capillary break adjacent the alignment structure. The capillary break may be configured to impede or prevent the formation of capillary paths between the ink reservoir and the lid.